Pulsed-Field Ablation Using a Novel Ablation-Mapping Integrated System for Pulmonary Vein Isolation—A Preliminary Animal Study

Abstract

Objective: The purpose of this study is to evaluate the preliminary safety and effect of a pulsed electric field (PEF) ablation system. Methods: The pulmonary veins (PVs) and superior vena cava (SVC) were isolated with the pulsed field ablation (PFA) system, which included a PEF generator and an electrode. The effects of PFA were investigated in six porcines using a novel circular catheter with combined functions (mapping/ablation) designed to work with a cardiac mapping system. The PEF generator delivered a train of biphasic pulsed electric pulses with a high amplitude (800–2000 V) and short pulse duration. The voltage mapping, PVs and SVC potentials, ostial diameters, and phrenic nerve and esophagus viability data were collected 4 weeks later, after which the animals were subsequently euthanized for gross histopathology analysis. Results: PFA 100% isolated the PVs and SVC with four applications with a mean pulse number of 100–150 pulses, causing no muscle convulsion. PFA does not cause PV stenosis or phrenic nerve dysfunction. Histological analysis confirmed 100% transmurally without any venous stenoses or phrenic injuries. Pathology follow-up showed that PFA had selectively ablated cardiomyocytes but spared blood vessels, the esophagus, and phrenic nerves; after ablation, the myocardial tissue showed homogeneous fibrosis. Conclusion: The PFA system is safe and feasible in the preliminary porcine model, which can effectively isolate PVs and SVCs. Transmural tissue damage can be achieved without phrenic palsy or stenosis.

Ablating Myocardium Using Nanosecond Pulsed Electric Fields: Preclinical Assessment of Feasibility, Safety, and Durability

“…A limitation of prior esophageal assessments after cardiac PFA was the chronic nature of the assessments. 13 – 15 , 20 , 21 As we have demonstrated in this report, esophageal lesions may be missed unless looked for within the early postablation period (2 to 3 days). Longer survival periods, in our report revealed minimal to no evidence of esophageal effects, suggesting that acute PFA lesions heal without significant residual damage.…”

Cardiac blood vessels and irreversible electroporation: findings from pulsed field ablation

“…Of these in vivo studies, only the large animal studies were designed to recapitulate clinically relevant methodologies regarding atrial tachyarrhythmia catheter ablation techniques in the appropriate anatomic structures. Nine studies were identified, seven conducted in various swine models [44][45][46][47][48][49][50] and two conducted in canine models [51,52] . Study designs and sample sizes varied widely [Table 1], and study durations ranged from 3 days [47,52] to 3 months; however, no pulmonary vein stenosis was reported in any of these preclinical studies.…”

Endocardial Pulsed Field Ablation and the Oesophagus: Are Atrio-oesophageal Fistulas Now History?

“…3,8,9 Other approaches used to deliver supratherapeutic PFA to the oesophagus include ablation from within the aorta towards the oesophagus, or from within the cardiac chambers close to the oesophagus, but without deviation. [12][13][14] The published reports employing these assessments for PFA technologies all had a survival period of 14-30 days; none reported any oesophageal damage even on histology after PFA. 3,[8][9][10][11][12][13][14] Two additional preliminary reports using the deviation model described the presence of oesophageal lesions secondary to PFA exposure; however, they differ from the above reports in that the oesophagus was examined at the acute time point (short-term survival).…”

“…[12][13][14] The published reports employing these assessments for PFA technologies all had a survival period of 14-30 days; none reported any oesophageal damage even on histology after PFA. 3,[8][9][10][11][12][13][14] Two additional preliminary reports using the deviation model described the presence of oesophageal lesions secondary to PFA exposure; however, they differ from the above reports in that the oesophagus was examined at the acute time point (short-term survival). 15,16 One of these reports examined the oesophagus at 2 hours and the other at 48 hours post-ablation.…”